The present invention relates to fibers, such as hollow fibers, which can be useful as dialysis membrane fibers, as well as methods and materials for manufacturing the same. Existing hollow fibers have unsatisfactory sieving curves for middle molecule removal. In the case of dialysis, the molecular weight of uremic toxins can vary over a large range. Most dialysis fibers can remove only solutes at the low end of the molecular weight spectrum. The failure of these existing dialysis products to remove larger uremic solutes from the blood can compromise the health of dialysis patients.
In addition, current polysulfone fibers are made with several types of polyvinylpyrrolidone and thus the resulting fiber can contain several types of polyvinylpyrrolidone (PVP). Several molecular weight types can be used, such as one or more low molecular weight PVPs with one or more high molecular weight PVPs. This can be a complicated formulation to work with and can cause inconsistency in product performance.
Accordingly, a need exists for fibers that can be formed into dialysis membranes with better middle and higher molecular weight solute removal. A further need exist for simplifying the formulation for PVP content in fiber formulations.